Titre
Protonation Equilibria of Hoechst 33258 in Aqueous Solution
Type
article
Institution
Externe
Périodique
Auteur(s)
Ladinig, Manfred
Auteure/Auteur
Leupin, Werner
Auteure/Auteur
Meuwly, Markus
Auteure/Auteur
Respondek, Michal
Auteure/Auteur
Wirz, Jakob
Auteure/Auteur
Zoete, Vincent
Auteure/Auteur
Liens vers les personnes
ISSN
0018-019X
Statut éditorial
Publié
Date de publication
2005-01-24
Volume
88
Numéro
1
Première page
53
Dernière page/numéro d’article
67
Peer-reviewed
Oui
Langue
anglais
Résumé
The bis‐benzimidazole derivative Hoechst 33258 (2′‐(4‐hydroxyphenyl)‐5‐(4‐methylpiperazin‐1‐yl)‐2,5′‐bi‐1H‐benzimidazole) binds to the minor groove of DNA duplexes and is widely used as fluorescent cytological stain for DNA. The neutral compound, 1, is amphiphilic with four basic and three acidic sites. We have determined all seven acidity constants by spectrophotometric titration to define the pH‐dependent distribution of species, from the fully protonated tetracation 14+ to the fully deprotonated trianion 13−, in aqueous solution. The structures of the intermediate protonation states were assigned with the aid of density‐functional calculations. Electrostatic interaction free energies were calculated to adjust the acidity constants of the molecular subunits of 1 to their environment in the species 14+ to 13−. The experimental and theoretical pKa values agree well, but they differ substantially from previous estimates given in the literature.
PID Serval
serval:BIB_2C1662BCE55B
Date de création
2019-01-22T09:48:32.035Z
Date de création dans IRIS
2025-05-20T16:50:10Z
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Nom
Ladinig_et_al-2005-Helvetica_Chimica_Acta.pdf
Version du manuscrit
published
Taille
339.06 KB
Format
Adobe PDF
PID Serval
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